git.oblomov.eu Git - linux-2.6/blob - fs/gfs2/log.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/gfs2_ondisk.h>
  16 #include <linux/crc32.h>
  17 #include <linux/lm_interface.h>
  18 #include <linux/delay.h>
  19 #include <linux/kthread.h>
  20 #include <linux/freezer.h>
  21 #include <linux/bio.h>
  22
  23 #include "gfs2.h"
  24 #include "incore.h"
  25 #include "bmap.h"
  26 #include "glock.h"
  27 #include "log.h"
  28 #include "lops.h"
  29 #include "meta_io.h"
  30 #include "util.h"
  31 #include "dir.h"
  32
  33 #define PULL 1
  34
  35 /**
  36  * gfs2_struct2blk - compute stuff
  37  * @sdp: the filesystem
  38  * @nstruct: the number of structures
  39  * @ssize: the size of the structures
  40  *
  41  * Compute the number of log descriptor blocks needed to hold a certain number
  42  * of structures of a certain size.
  43  *
  44  * Returns: the number of blocks needed (minimum is always 1)
  45  */
  46
  47 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
  48                              unsigned int ssize)
  49 {
  50         unsigned int blks;
  51         unsigned int first, second;
  52
  53         blks = 1;
  54         first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
  55
  56         if (nstruct > first) {
  57                 second = (sdp->sd_sb.sb_bsize -
  58                           sizeof(struct gfs2_meta_header)) / ssize;
  59                 blks += DIV_ROUND_UP(nstruct - first, second);
  60         }
  61
  62         return blks;
  63 }
  64
  65 /**
  66  * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
  67  * @mapping: The associated mapping (maybe NULL)
  68  * @bd: The gfs2_bufdata to remove
  69  *
  70  * The log lock _must_ be held when calling this function
  71  *
  72  */
  73
  74 void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
  75 {
  76         bd->bd_ail = NULL;
  77         list_del_init(&bd->bd_ail_st_list);
  78         list_del_init(&bd->bd_ail_gl_list);
  79         atomic_dec(&bd->bd_gl->gl_ail_count);
  80         brelse(bd->bd_bh);
  81 }
  82
  83 /**
  84  * gfs2_ail1_start_one - Start I/O on a part of the AIL
  85  * @sdp: the filesystem
  86  * @tr: the part of the AIL
  87  *
  88  */
  89
  90 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
  91 __releases(&sdp->sd_log_lock)
  92 __acquires(&sdp->sd_log_lock)
  93 {
  94         struct gfs2_bufdata *bd, *s;
  95         struct buffer_head *bh;
  96         int retry;
  97
  98         do {
  99                 retry = 0;
 100
 101                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 102                                                  bd_ail_st_list) {
 103                         bh = bd->bd_bh;
 104
 105                         gfs2_assert(sdp, bd->bd_ail == ai);
 106
 107                         if (!buffer_busy(bh)) {
 108                                 if (!buffer_uptodate(bh))
 109                                         gfs2_io_error_bh(sdp, bh);
 110                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 111                                 continue;
 112                         }
 113
 114                         if (!buffer_dirty(bh))
 115                                 continue;
 116
 117                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 118
 119                         get_bh(bh);
 120                         gfs2_log_unlock(sdp);
 121                         lock_buffer(bh);
 122                         if (test_clear_buffer_dirty(bh)) {
 123                                 bh->b_end_io = end_buffer_write_sync;
 124                                 submit_bh(WRITE, bh);
 125                         } else {
 126                                 unlock_buffer(bh);
 127                                 brelse(bh);
 128                         }
 129                         gfs2_log_lock(sdp);
 130
 131                         retry = 1;
 132                         break;
 133                 }
 134         } while (retry);
 135 }
 136
 137 /**
 138  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 139  * @sdp: the filesystem
 140  * @ai: the AIL entry
 141  *
 142  */
 143
 144 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 145 {
 146         struct gfs2_bufdata *bd, *s;
 147         struct buffer_head *bh;
 148
 149         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 150                                          bd_ail_st_list) {
 151                 bh = bd->bd_bh;
 152
 153                 gfs2_assert(sdp, bd->bd_ail == ai);
 154
 155                 if (buffer_busy(bh)) {
 156                         if (flags & DIO_ALL)
 157                                 continue;
 158                         else
 159                                 break;
 160                 }
 161
 162                 if (!buffer_uptodate(bh))
 163                         gfs2_io_error_bh(sdp, bh);
 164
 165                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 166         }
 167
 168         return list_empty(&ai->ai_ail1_list);
 169 }
 170
 171 static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
 172 {
 173         struct list_head *head;
 174         u64 sync_gen;
 175         struct list_head *first;
 176         struct gfs2_ail *first_ai, *ai, *tmp;
 177         int done = 0;
 178
 179         gfs2_log_lock(sdp);
 180         head = &sdp->sd_ail1_list;
 181         if (list_empty(head)) {
 182                 gfs2_log_unlock(sdp);
 183                 return;
 184         }
 185         sync_gen = sdp->sd_ail_sync_gen++;
 186
 187         first = head->prev;
 188         first_ai = list_entry(first, struct gfs2_ail, ai_list);
 189         first_ai->ai_sync_gen = sync_gen;
 190         gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */
 191
 192         if (flags & DIO_ALL)
 193                 first = NULL;
 194
 195         while(!done) {
 196                 if (first && (head->prev != first ||
 197                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
 198                         break;
 199
 200                 done = 1;
 201                 list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) {
 202                         if (ai->ai_sync_gen >= sync_gen)
 203                                 continue;
 204                         ai->ai_sync_gen = sync_gen;
 205                         gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
 206                         done = 0;
 207                         break;
 208                 }
 209         }
 210
 211         gfs2_log_unlock(sdp);
 212 }
 213
 214 static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
 215 {
 216         struct gfs2_ail *ai, *s;
 217         int ret;
 218
 219         gfs2_log_lock(sdp);
 220
 221         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
 222                 if (gfs2_ail1_empty_one(sdp, ai, flags))
 223                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
 224                 else if (!(flags & DIO_ALL))
 225                         break;
 226         }
 227
 228         ret = list_empty(&sdp->sd_ail1_list);
 229
 230         gfs2_log_unlock(sdp);
 231
 232         return ret;
 233 }
 234
 235
 236 /**
 237  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 238  * @sdp: the filesystem
 239  * @ai: the AIL entry
 240  *
 241  */
 242
 243 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 244 {
 245         struct list_head *head = &ai->ai_ail2_list;
 246         struct gfs2_bufdata *bd;
 247
 248         while (!list_empty(head)) {
 249                 bd = list_entry(head->prev, struct gfs2_bufdata,
 250                                 bd_ail_st_list);
 251                 gfs2_assert(sdp, bd->bd_ail == ai);
 252                 gfs2_remove_from_ail(bd);
 253         }
 254 }
 255
 256 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 257 {
 258         struct gfs2_ail *ai, *safe;
 259         unsigned int old_tail = sdp->sd_log_tail;
 260         int wrap = (new_tail < old_tail);
 261         int a, b, rm;
 262
 263         gfs2_log_lock(sdp);
 264
 265         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 266                 a = (old_tail <= ai->ai_first);
 267                 b = (ai->ai_first < new_tail);
 268                 rm = (wrap) ? (a || b) : (a && b);
 269                 if (!rm)
 270                         continue;
 271
 272                 gfs2_ail2_empty_one(sdp, ai);
 273                 list_del(&ai->ai_list);
 274                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 275                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 276                 kfree(ai);
 277         }
 278
 279         gfs2_log_unlock(sdp);
 280 }
 281
 282 /**
 283  * gfs2_log_reserve - Make a log reservation
 284  * @sdp: The GFS2 superblock
 285  * @blks: The number of blocks to reserve
 286  *
 287  * Note that we never give out the last few blocks of the journal. Thats
 288  * due to the fact that there is a small number of header blocks
 289  * associated with each log flush. The exact number can't be known until
 290  * flush time, so we ensure that we have just enough free blocks at all
 291  * times to avoid running out during a log flush.
 292  *
 293  * Returns: errno
 294  */
 295
 296 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 297 {
 298         unsigned int try = 0;
 299         unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
 300
 301         if (gfs2_assert_warn(sdp, blks) ||
 302             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 303                 return -EINVAL;
 304
 305         mutex_lock(&sdp->sd_log_reserve_mutex);
 306         gfs2_log_lock(sdp);
 307         while(atomic_read(&sdp->sd_log_blks_free) <= (blks + reserved_blks)) {
 308                 gfs2_log_unlock(sdp);
 309                 gfs2_ail1_empty(sdp, 0);
 310                 gfs2_log_flush(sdp, NULL);
 311
 312                 if (try++)
 313                         gfs2_ail1_start(sdp, 0);
 314                 gfs2_log_lock(sdp);
 315         }
 316         atomic_sub(blks, &sdp->sd_log_blks_free);
 317         gfs2_log_unlock(sdp);
 318         mutex_unlock(&sdp->sd_log_reserve_mutex);
 319
 320         down_read(&sdp->sd_log_flush_lock);
 321
 322         return 0;
 323 }
 324
 325 /**
 326  * gfs2_log_release - Release a given number of log blocks
 327  * @sdp: The GFS2 superblock
 328  * @blks: The number of blocks
 329  *
 330  */
 331
 332 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 333 {
 334
 335         gfs2_log_lock(sdp);
 336         atomic_add(blks, &sdp->sd_log_blks_free);
 337         gfs2_assert_withdraw(sdp,
 338                              atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks);
 339         gfs2_log_unlock(sdp);
 340         up_read(&sdp->sd_log_flush_lock);
 341 }
 342
 343 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 344 {
 345         struct gfs2_journal_extent *je;
 346
 347         list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) {
 348                 if (lbn >= je->lblock && lbn < je->lblock + je->blocks)
 349                         return je->dblock + lbn - je->lblock;
 350         }
 351
 352         return -1;
 353 }
 354
 355 /**
 356  * log_distance - Compute distance between two journal blocks
 357  * @sdp: The GFS2 superblock
 358  * @newer: The most recent journal block of the pair
 359  * @older: The older journal block of the pair
 360  *
 361  *   Compute the distance (in the journal direction) between two
 362  *   blocks in the journal
 363  *
 364  * Returns: the distance in blocks
 365  */
 366
 367 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 368                                         unsigned int older)
 369 {
 370         int dist;
 371
 372         dist = newer - older;
 373         if (dist < 0)
 374                 dist += sdp->sd_jdesc->jd_blocks;
 375
 376         return dist;
 377 }
 378
 379 /**
 380  * calc_reserved - Calculate the number of blocks to reserve when
 381  *                 refunding a transaction's unused buffers.
 382  * @sdp: The GFS2 superblock
 383  *
 384  * This is complex.  We need to reserve room for all our currently used
 385  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
 386  * all our journaled data buffers for journaled files (e.g. files in the
 387  * meta_fs like rindex, or files for which chattr +j was done.)
 388  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
 389  * will count it as free space (sd_log_blks_free) and corruption will follow.
 390  *
 391  * We can have metadata bufs and jdata bufs in the same journal.  So each
 392  * type gets its own log header, for which we need to reserve a block.
 393  * In fact, each type has the potential for needing more than one header
 394  * in cases where we have more buffers than will fit on a journal page.
 395  * Metadata journal entries take up half the space of journaled buffer entries.
 396  * Thus, metadata entries have buf_limit (502) and journaled buffers have
 397  * databuf_limit (251) before they cause a wrap around.
 398  *
 399  * Also, we need to reserve blocks for revoke journal entries and one for an
 400  * overall header for the lot.
 401  *
 402  * Returns: the number of blocks reserved
 403  */
 404 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 405 {
 406         unsigned int reserved = 0;
 407         unsigned int mbuf_limit, metabufhdrs_needed;
 408         unsigned int dbuf_limit, databufhdrs_needed;
 409         unsigned int revokes = 0;
 410
 411         mbuf_limit = buf_limit(sdp);
 412         metabufhdrs_needed = (sdp->sd_log_commited_buf +
 413                               (mbuf_limit - 1)) / mbuf_limit;
 414         dbuf_limit = databuf_limit(sdp);
 415         databufhdrs_needed = (sdp->sd_log_commited_databuf +
 416                               (dbuf_limit - 1)) / dbuf_limit;
 417
 418         if (sdp->sd_log_commited_revoke)
 419                 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 420                                           sizeof(u64));
 421
 422         reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
 423                 sdp->sd_log_commited_databuf + databufhdrs_needed +
 424                 revokes;
 425         /* One for the overall header */
 426         if (reserved)
 427                 reserved++;
 428         return reserved;
 429 }
 430
 431 static unsigned int current_tail(struct gfs2_sbd *sdp)
 432 {
 433         struct gfs2_ail *ai;
 434         unsigned int tail;
 435
 436         gfs2_log_lock(sdp);
 437
 438         if (list_empty(&sdp->sd_ail1_list)) {
 439                 tail = sdp->sd_log_head;
 440         } else {
 441                 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
 442                 tail = ai->ai_first;
 443         }
 444
 445         gfs2_log_unlock(sdp);
 446
 447         return tail;
 448 }
 449
 450 void gfs2_log_incr_head(struct gfs2_sbd *sdp)
 451 {
 452         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 453                 BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head);
 454
 455         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 456                 sdp->sd_log_flush_head = 0;
 457                 sdp->sd_log_flush_wrapped = 1;
 458         }
 459 }
 460
 461 /**
 462  * gfs2_log_write_endio - End of I/O for a log buffer
 463  * @bh: The buffer head
 464  * @uptodate: I/O Status
 465  *
 466  */
 467
 468 static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
 469 {
 470         struct gfs2_sbd *sdp = bh->b_private;
 471         bh->b_private = NULL;
 472
 473         end_buffer_write_sync(bh, uptodate);
 474         if (atomic_dec_and_test(&sdp->sd_log_in_flight))
 475                 wake_up(&sdp->sd_log_flush_wait);
 476 }
 477
 478 /**
 479  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 480  * @sdp: The GFS2 superblock
 481  *
 482  * Returns: the buffer_head
 483  */
 484
 485 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 486 {
 487         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 488         struct buffer_head *bh;
 489
 490         bh = sb_getblk(sdp->sd_vfs, blkno);
 491         lock_buffer(bh);
 492         memset(bh->b_data, 0, bh->b_size);
 493         set_buffer_uptodate(bh);
 494         clear_buffer_dirty(bh);
 495         gfs2_log_incr_head(sdp);
 496         atomic_inc(&sdp->sd_log_in_flight);
 497         bh->b_private = sdp;
 498         bh->b_end_io = gfs2_log_write_endio;
 499
 500         return bh;
 501 }
 502
 503 /**
 504  * gfs2_fake_write_endio -
 505  * @bh: The buffer head
 506  * @uptodate: The I/O Status
 507  *
 508  */
 509
 510 static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
 511 {
 512         struct buffer_head *real_bh = bh->b_private;
 513         struct gfs2_bufdata *bd = real_bh->b_private;
 514         struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
 515
 516         end_buffer_write_sync(bh, uptodate);
 517         free_buffer_head(bh);
 518         unlock_buffer(real_bh);
 519         brelse(real_bh);
 520         if (atomic_dec_and_test(&sdp->sd_log_in_flight))
 521                 wake_up(&sdp->sd_log_flush_wait);
 522 }
 523
 524 /**
 525  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 526  * @sdp: the filesystem
 527  * @data: the data the buffer_head should point to
 528  *
 529  * Returns: the log buffer descriptor
 530  */
 531
 532 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 533                                       struct buffer_head *real)
 534 {
 535         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 536         struct buffer_head *bh;
 537
 538         bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 539         atomic_set(&bh->b_count, 1);
 540         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
 541         set_bh_page(bh, real->b_page, bh_offset(real));
 542         bh->b_blocknr = blkno;
 543         bh->b_size = sdp->sd_sb.sb_bsize;
 544         bh->b_bdev = sdp->sd_vfs->s_bdev;
 545         bh->b_private = real;
 546         bh->b_end_io = gfs2_fake_write_endio;
 547
 548         gfs2_log_incr_head(sdp);
 549         atomic_inc(&sdp->sd_log_in_flight);
 550
 551         return bh;
 552 }
 553
 554 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 555 {
 556         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 557
 558         ail2_empty(sdp, new_tail);
 559
 560         gfs2_log_lock(sdp);
 561         atomic_add(dist, &sdp->sd_log_blks_free);
 562         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks);
 563         gfs2_log_unlock(sdp);
 564
 565         sdp->sd_log_tail = new_tail;
 566 }
 567
 568 /**
 569  * log_write_header - Get and initialize a journal header buffer
 570  * @sdp: The GFS2 superblock
 571  *
 572  * Returns: the initialized log buffer descriptor
 573  */
 574
 575 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 576 {
 577         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 578         struct buffer_head *bh;
 579         struct gfs2_log_header *lh;
 580         unsigned int tail;
 581         u32 hash;
 582
 583         bh = sb_getblk(sdp->sd_vfs, blkno);
 584         lock_buffer(bh);
 585         memset(bh->b_data, 0, bh->b_size);
 586         set_buffer_uptodate(bh);
 587         clear_buffer_dirty(bh);
 588
 589         gfs2_ail1_empty(sdp, 0);
 590         tail = current_tail(sdp);
 591
 592         lh = (struct gfs2_log_header *)bh->b_data;
 593         memset(lh, 0, sizeof(struct gfs2_log_header));
 594         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 595         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 596         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 597         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
 598         lh->lh_flags = cpu_to_be32(flags);
 599         lh->lh_tail = cpu_to_be32(tail);
 600         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
 601         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 602         lh->lh_hash = cpu_to_be32(hash);
 603
 604         bh->b_end_io = end_buffer_write_sync;
 605         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
 606                 goto skip_barrier;
 607         get_bh(bh);
 608         submit_bh(WRITE_BARRIER | (1 << BIO_RW_META), bh);
 609         wait_on_buffer(bh);
 610         if (buffer_eopnotsupp(bh)) {
 611                 clear_buffer_eopnotsupp(bh);
 612                 set_buffer_uptodate(bh);
 613                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
 614                 lock_buffer(bh);
 615 skip_barrier:
 616                 get_bh(bh);
 617                 submit_bh(WRITE_SYNC | (1 << BIO_RW_META), bh);
 618                 wait_on_buffer(bh);
 619         }
 620         if (!buffer_uptodate(bh))
 621                 gfs2_io_error_bh(sdp, bh);
 622         brelse(bh);
 623
 624         if (sdp->sd_log_tail != tail)
 625                 log_pull_tail(sdp, tail);
 626         else
 627                 gfs2_assert_withdraw(sdp, !pull);
 628
 629         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 630         gfs2_log_incr_head(sdp);
 631 }
 632
 633 static void log_flush_commit(struct gfs2_sbd *sdp)
 634 {
 635         DEFINE_WAIT(wait);
 636
 637         if (atomic_read(&sdp->sd_log_in_flight)) {
 638                 do {
 639                         prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
 640                                         TASK_UNINTERRUPTIBLE);
 641                         if (atomic_read(&sdp->sd_log_in_flight))
 642                                 io_schedule();
 643                 } while(atomic_read(&sdp->sd_log_in_flight));
 644                 finish_wait(&sdp->sd_log_flush_wait, &wait);
 645         }
 646
 647         log_write_header(sdp, 0, 0);
 648 }
 649
 650 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 651 {
 652         struct gfs2_bufdata *bd;
 653         struct buffer_head *bh;
 654         LIST_HEAD(written);
 655
 656         gfs2_log_lock(sdp);
 657         while (!list_empty(&sdp->sd_log_le_ordered)) {
 658                 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
 659                 list_move(&bd->bd_le.le_list, &written);
 660                 bh = bd->bd_bh;
 661                 if (!buffer_dirty(bh))
 662                         continue;
 663                 get_bh(bh);
 664                 gfs2_log_unlock(sdp);
 665                 lock_buffer(bh);
 666                 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
 667                         bh->b_end_io = end_buffer_write_sync;
 668                         submit_bh(WRITE, bh);
 669                 } else {
 670                         unlock_buffer(bh);
 671                         brelse(bh);
 672                 }
 673                 gfs2_log_lock(sdp);
 674         }
 675         list_splice(&written, &sdp->sd_log_le_ordered);
 676         gfs2_log_unlock(sdp);
 677 }
 678
 679 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
 680 {
 681         struct gfs2_bufdata *bd;
 682         struct buffer_head *bh;
 683
 684         gfs2_log_lock(sdp);
 685         while (!list_empty(&sdp->sd_log_le_ordered)) {
 686                 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list);
 687                 bh = bd->bd_bh;
 688                 if (buffer_locked(bh)) {
 689                         get_bh(bh);
 690                         gfs2_log_unlock(sdp);
 691                         wait_on_buffer(bh);
 692                         brelse(bh);
 693                         gfs2_log_lock(sdp);
 694                         continue;
 695                 }
 696                 list_del_init(&bd->bd_le.le_list);
 697         }
 698         gfs2_log_unlock(sdp);
 699 }
 700
 701 /**
 702  * gfs2_log_flush - flush incore transaction(s)
 703  * @sdp: the filesystem
 704  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 705  *
 706  */
 707
 708 void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 709 {
 710         struct gfs2_ail *ai;
 711
 712         down_write(&sdp->sd_log_flush_lock);
 713
 714         /* Log might have been flushed while we waited for the flush lock */
 715         if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
 716                 up_write(&sdp->sd_log_flush_lock);
 717                 return;
 718         }
 719
 720         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 721         INIT_LIST_HEAD(&ai->ai_ail1_list);
 722         INIT_LIST_HEAD(&ai->ai_ail2_list);
 723
 724         if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
 725                 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
 726                        sdp->sd_log_commited_buf);
 727                 gfs2_assert_withdraw(sdp, 0);
 728         }
 729         if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
 730                 printk(KERN_INFO "GFS2: log databuf %u %u\n",
 731                        sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
 732                 gfs2_assert_withdraw(sdp, 0);
 733         }
 734         gfs2_assert_withdraw(sdp,
 735                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 736
 737         sdp->sd_log_flush_head = sdp->sd_log_head;
 738         sdp->sd_log_flush_wrapped = 0;
 739         ai->ai_first = sdp->sd_log_flush_head;
 740
 741         gfs2_ordered_write(sdp);
 742         lops_before_commit(sdp);
 743         gfs2_ordered_wait(sdp);
 744
 745         if (sdp->sd_log_head != sdp->sd_log_flush_head)
 746                 log_flush_commit(sdp);
 747         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 748                 gfs2_log_lock(sdp);
 749                 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
 750                 gfs2_log_unlock(sdp);
 751                 log_write_header(sdp, 0, PULL);
 752         }
 753         lops_after_commit(sdp, ai);
 754
 755         gfs2_log_lock(sdp);
 756         sdp->sd_log_head = sdp->sd_log_flush_head;
 757         sdp->sd_log_blks_reserved = 0;
 758         sdp->sd_log_commited_buf = 0;
 759         sdp->sd_log_commited_databuf = 0;
 760         sdp->sd_log_commited_revoke = 0;
 761
 762         if (!list_empty(&ai->ai_ail1_list)) {
 763                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 764                 ai = NULL;
 765         }
 766         gfs2_log_unlock(sdp);
 767
 768         sdp->sd_vfs->s_dirt = 0;
 769         up_write(&sdp->sd_log_flush_lock);
 770
 771         kfree(ai);
 772 }
 773
 774 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 775 {
 776         unsigned int reserved;
 777         unsigned int unused;
 778
 779         gfs2_log_lock(sdp);
 780
 781         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 782         sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
 783                 tr->tr_num_databuf_rm;
 784         gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
 785                              (((int)sdp->sd_log_commited_databuf) >= 0));
 786         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 787         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 788         reserved = calc_reserved(sdp);
 789         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
 790         unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
 791         atomic_add(unused, &sdp->sd_log_blks_free);
 792         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
 793                              sdp->sd_jdesc->jd_blocks);
 794         sdp->sd_log_blks_reserved = reserved;
 795
 796         gfs2_log_unlock(sdp);
 797 }
 798
 799 static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 800 {
 801         struct list_head *head = &tr->tr_list_buf;
 802         struct gfs2_bufdata *bd;
 803
 804         gfs2_log_lock(sdp);
 805         while (!list_empty(head)) {
 806                 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
 807                 list_del_init(&bd->bd_list_tr);
 808                 tr->tr_num_buf--;
 809         }
 810         gfs2_log_unlock(sdp);
 811         gfs2_assert_warn(sdp, !tr->tr_num_buf);
 812 }
 813
 814 /**
 815  * gfs2_log_commit - Commit a transaction to the log
 816  * @sdp: the filesystem
 817  * @tr: the transaction
 818  *
 819  * Returns: errno
 820  */
 821
 822 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 823 {
 824         log_refund(sdp, tr);
 825         buf_lo_incore_commit(sdp, tr);
 826
 827         sdp->sd_vfs->s_dirt = 1;
 828         up_read(&sdp->sd_log_flush_lock);
 829
 830         gfs2_log_lock(sdp);
 831         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks))
 832                 wake_up_process(sdp->sd_logd_process);
 833         gfs2_log_unlock(sdp);
 834 }
 835
 836 /**
 837  * gfs2_log_shutdown - write a shutdown header into a journal
 838  * @sdp: the filesystem
 839  *
 840  */
 841
 842 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 843 {
 844         down_write(&sdp->sd_log_flush_lock);
 845
 846         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 847         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 848         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 849         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 850         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 851         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 852
 853         sdp->sd_log_flush_head = sdp->sd_log_head;
 854         sdp->sd_log_flush_wrapped = 0;
 855
 856         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
 857                          (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
 858
 859         gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
 860         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 861         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 862
 863         sdp->sd_log_head = sdp->sd_log_flush_head;
 864         sdp->sd_log_tail = sdp->sd_log_head;
 865
 866         up_write(&sdp->sd_log_flush_lock);
 867 }
 868
 869
 870 /**
 871  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 872  * @sdp: the filesystem
 873  *
 874  */
 875
 876 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 877 {
 878         gfs2_log_flush(sdp, NULL);
 879         for (;;) {
 880                 gfs2_ail1_start(sdp, DIO_ALL);
 881                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 882                         break;
 883                 msleep(10);
 884         }
 885 }
 886
 887
 888 /**
 889  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
 890  * @sdp: Pointer to GFS2 superblock
 891  *
 892  * Also, periodically check to make sure that we're using the most recent
 893  * journal index.
 894  */
 895
 896 int gfs2_logd(void *data)
 897 {
 898         struct gfs2_sbd *sdp = data;
 899         unsigned long t;
 900         int need_flush;
 901
 902         while (!kthread_should_stop()) {
 903                 /* Advance the log tail */
 904
 905                 t = sdp->sd_log_flush_time +
 906                     gfs2_tune_get(sdp, gt_log_flush_secs) * HZ;
 907
 908                 gfs2_ail1_empty(sdp, DIO_ALL);
 909                 gfs2_log_lock(sdp);
 910                 need_flush = sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks);
 911                 gfs2_log_unlock(sdp);
 912                 if (need_flush || time_after_eq(jiffies, t)) {
 913                         gfs2_log_flush(sdp, NULL);
 914                         sdp->sd_log_flush_time = jiffies;
 915                 }
 916
 917                 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
 918                 if (freezing(current))
 919                         refrigerator();
 920                 schedule_timeout_interruptible(t);
 921         }
 922
 923         return 0;
 924 }
 925